Friday, October 29, 2010

A milestone for molecular beams: The ring in question consists of 40 electrostatic focusing elements called hexapoles. The hexapoles keep a packet of molecules (for this experiment, ammonia) confined to a circular orbit. Even though we think of these types of machines as rather large, the setup in question is reasonably compact. “It fits almost on my table,” Meijer says. “The diameter is about 50 centimeters, making it possible to do the kinds of experiments we suggest with relative ease.”
The ring setup allows for the injection of 19 separate packets of molecules, all of them moving at the same pace, trailing each other by a fixed distance. Meijer and his colleagues were able to keep this up as the molecule packets made enough round trips through the ring to surpass the distance of a mile. “Interesting things happen when you can store molecules that long,” Meijer points out. “We’ve found that there are interesting things that happen with black body radiation, and this device could be one way to study these effects without the normally complicated experiments seen in the past.”